Noun
English Wikipedia has an article on:White phosphorusWikipedia
white phosphorus (uncountable)
(chemistry) The most common allotrope of phosphorus; a yellow-white waxy solid that is insoluble in water and spontaneously combusts on exposure to air to form clouds of phosphorus pentoxide; used as a military smokescreen and as an incendiary weapon.
White phosphorus is insoluble in water but soluble in carbon disulfide. Source: Internet
White phosphorus smoke is used to start fires, burn a target, or to create smoke which is useful in concealing the movements of friendly units. Source: Internet